Question

我正在尝试使用下拉列表更改google-map中的半径圆，例如当我从下拉列表中选择2 km时，它将被设置为2.0半径，如果我选择4 km则将设置为4.0到半径。在这一点上，一切都工作得很完美，但现在问题是在第二次选择第一个存在时，没有从圆圈中删除。

我的代码：

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title></title>
<script type='text/javascript' src='http://code.jquery.com/jquery-1.7.1.js'></script>
<link rel="stylesheet" type="text/css" href="/css/normalize.css">
<link rel="stylesheet" type="text/css" href="/css/result-light.css">

<style type='text/css'>
#map_canvas {
    background:#ccc;
    height:400px;
    width:50%;
    margin-top:15px;
}
</style>

<select name="distance" id="distance">
  <option value="0.5" selected="selected">0.5 km</option>
  <option value="1.0">1 km</option>
  <option value="2.0">2 km</option>
  <option value="3.0">3 km</option>
  <option value="4.0">4 km</option>
  <option value="5.0">5 km</option>
</select>

<script type='text/javascript'>//<![CDATA[ 
jQuery.noConflict();
jQuery(document).ready(function() {
var subjectRange;
var myOptions = {
  zoom: 13,
  center: latlng,
  mapTypeId: google.maps.MapTypeId.ROADMAP
}
map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
var locations = ['1.280095,103.850949'];

/**
 * Draw points and check whether those points are inside a range from a point.
*/
var subjectPoint = {
    point: new google.maps.LatLng(1.280095,103.850949),
    radius: 1.0, //default radius
    color: '#00AA00',
}
var elevator;   

var map;
var geocoder = new google.maps.Geocoder();
var latlng = new google.maps.LatLng(1.280095,103.850949);

//render the range
var subjectMarker = new google.maps.Marker({
    position: subjectPoint.point,
    title: 'Subject',
});
var subjectRange = new google.maps.Circle({
    map: map,
    radius: subjectPoint.radius * 1000,    // metres
    fillColor: subjectPoint.color,
                strokeColor: '#3D9912'
});
subjectRange.bindTo('center', subjectMarker, 'position');



function codeAddress(locations) {

    for (i = 0; i < locations.length; i++) {
        geocoder.geocode( { 'address': locations[i]}, function(results, status) {
            if (status == google.maps.GeocoderStatus.OK) {
                map.setCenter(results[0].geometry.location);
                var marker = new google.maps.Marker({
                    map: map, 
                    position: results[0].geometry.location
                });
            } else {
                alert("Geocode was not successful for the following reason: " + status);
            }
        });
    }
}
codeAddress(locations);


jQuery('#distance').on('change', function() {
    alert(jQuery('select[name="distance"] option:selected').val()); 

                rad = jQuery('select[name="distance"] option:selected').val();
                //subjectRange.setMap(null);
                var subjectPoint = {
                    point: new google.maps.LatLng(1.280095,103.850949),
                    radius: rad,
                    color: '#00AA00',
                }       
                //render the range
                var subjectMarker = new google.maps.Marker({
                    position: subjectPoint.point,
                    title: 'Subject',
                });
                var subjectRange = new google.maps.Circle({
                    map: map,
                    radius: subjectPoint.radius * 1000,    // metres
                    fillColor: subjectPoint.color,
                    strokeColor: '#3D9912'
                });
                subjectRange.bindTo('center', subjectMarker, 'position');

   });
});//]]>  

</script>
</head>
<body>
<script type="text/javascript" src="http://maps.googleapis.com/maps/api/js?sensor=false"></script>
<div id="map_canvas">Google Map</div>
</body>
</html>

Answer 1

每次更改半径时，您都会创建一个新圆圈。只需更改现有圆的半径：

jQuery('#distance').on('change', function() {

            rad = jQuery('select[name="distance"] option:selected').val();
            //render the range
            subjectRange.setOptions({radius:rad * 1000});
});

working example

如何从谷歌地图中删除圆形半径

我的代码：

1 个答案: